Nakamura & Yamane Lab (a department of Tokyo University) has developed a pair of mid-size, light-weight humanoids to better test human-like motions in robotics. Around 2002, some manufacturers began to provide small motors, gears, and other parts developed using the same process as industrial, high-spec components that were suitable for robots about 50cm tall. This made it possible for them to develop their own humanoid robot systems.

Completed in 2003, the first prototype was nicknamed Mighty to reflect the roboticists’ desire to create mighty robots. It stands 58cm tall, weighs 6.5kg, and has 23 individual joints. The magnesium-alloy exoskeleton looks like something straight out of an anime, and has the added benefits of being both durable and light weight.

Mighty has an unusual joint structure compared to most humanoids in that the shoulder joint axis is slanted at a 45 degree angle (most humanoids have the joint positioned straight), which generates a natural human-like motion when the arms extend. This joint orientation does increase the overall size of the shoulder, but for this particular design it helps to emphasize the toughness of the robot. The hips are also designed to increase the range of motion, allowing the robot to perform the splits.